Background: Periprosthetic infections (PPI) represent one of the most complex complications in arthroplasty concerning both, diagnosis and therapy. The incidence of PPI of the hip is approximately 1 % after primary procedures and 4 % after revision surgery. About two thirds of PPIs occur via intraoperative contamination and the remaining PPIs are acquired by hematogenous seeding.
Aim: This article presents an overview of up to date evidence-based diagnostics and therapy of PPI of the hip with the establishment of a clear algorithm.
Methods: A selective literature search was carried out with the inclusion of own work.
Results: A PPI must be actively excluded in cases of a painful prosthesis or signs of loosening within the first years after implantation. Measurement of C-reactive protein (CRP) can be normal especially in cases of chronic (low grade) PPI and cannot be used as an exclusion criterion. The standard diagnostic procedure includes preoperative joint aspiration with culture and leukocyte counts as well as culture and histology of periprosthetic tissue. Imaging techniques, such as magnetic resonance imaging (MRI) and scintigraphy are of inferior significance. Newer methods, such as sonication of removed implants have revolutionized the diagnostics and several cases which had previously been considered aseptic loosening failures have now been reclassified as PPI. Essential parameters for the treatment algorithm are maturity of the biofilm, stability of the prosthesis, the causative organism and the state of the soft tissue. Retention of the prosthesis can only be considered when the biofilm is still immature (acute PPI). In chronic (low grade) PPI eradication of the infection can only be achieved by exchanging the prosthesis. This has to be performed either as a one-stage procedure or as a two-stage exchange with a short (2-4 weeks) or a long (> 6 weeks) interval. Biofilm active antibiotics play an essential role in the treatment of PPI and have to be used as targeted therapy.
Discussion: Successful therapy and diagnostics of PPI require following an exact algorithm. The interdisciplinary cooperation between specialists for infectious diseases and microbiologists represents a decisive factor.